Implementation of a self-sampling HPV test for non-responders to cervical cancer screening in Japan: secondary analysis of the ACCESS trial

A self-sampling human papillomavirus (HPV) test could improve the morbidity and mortality of cervical cancer in Japan. However, its effectiveness and feasibility have not been demonstrated sufficiently. Hence, we launched a randomized controlled trial, which is ongoing, and report the results of a secondary analysis. To ensure autonomous participation with a minimum selection bias, opt-out consent was obtained from women who met the inclusion criteria, and written consent was obtained from those who underwent a self-sampling test. The number of women who met the inclusion criteria was 20,555; 4283 and 1138 opted out before and after the assignment, respectively. Of the 7340 women in the self-sampling arm, 1372 (18.7%) ordered and 1196 (16.3%) underwent the test. Younger women in their 30 s and 40 s tended to undertake the test more frequently than older women in their 50 s (P for trend < 0.001). Invalid HPV test results were rare (1.3%), and neither adverse events nor serious complaints were reported. Despite adopting the opt-out procedure, more women than expected declined to participate, suggesting the need for a waiver of consent or assignment before consent to reduce selection bias. A self-sampling HPV test can be implemented in Japan and would be more accessible to young women, the predominant group affected by cervical cancer.


Endpoints of this secondary analysis Proportion of self-sampling human papillomavirus (HPV) tests ordered
The percentage of the participants who ordered the self-sampling HPV test was calculated. The denominator is the intention to screen (ITS) in the self-sampling arm, which includes all participants who were assigned to the self-sampling arm. The numerator is the number of participants who ordered the test.

Proportion of self-sampling HPV tests ordered through the website
The percentage of the participants who ordered the test through the website, in which the denominator is all participants who ordered the test, and the numerator is those who ordered through the website, was calculated.

Proportion of self-sampling HPV test kits returned
The proportions of the participants who underwent an HPV test with two different denominators and one numerator were calculated. The denominators are ITS in the selfsampling arm and the number of participants who ordered self-sampling HPV tests. The numerator is the number of participants who return both a sample and a filled consent form.

Proportion of positive HPV tests
The percentage of participants with a positive HPV test result was defined as the detection of DNA of the 14 high-risk HPV types (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The denominator is the number of participants who returned both a sample and a filled consent form. The numerator is the number of participants with a positive HPV test result.

Proportion of invalid HPV tests
The percentage of participants whose HPV test result was invalid was defined as the failure to detect DNA of the 14 high-risk HPV types and β-globin (internal cellular control). The denominator is the number of participants who returned both a sample and a filled consent form. The numerator is the number of participants whose HPV test result was invalid.

Time to order the test
The period between the time that the second invitation letter was sent to the participants and the time that the self-sampling HPV test was ordered by the participants was calculated. The participants to be analyzed were those who ordered the test.

Time to send a kit
The period between the time that the self-sampling HPV test was ordered and the time that the kit was sent to the participants was calculated. The participants to be analyzed were those who ordered the self-sampling HPV test.

Time to return a sample since sending the kit
The period between the time that the kit was sent to the participants and the time a sample was returned was calculated. The participants to be analyzed were those who returned both a sample and a filled consent form, and these participants were named "participants A."

Time to return a sample since collecting it
The period between the time that a sample was collected by the participants and the time that the sample was returned was calculated. The participants to be analyzed were those who returned both a sample and a filled consent form and reported the sample collection date.

Time to order the test to the laboratory
The period between the time that a sample was returned by the participants and the HPV test was ordered to the laboratory was calculated. The participants to be analyzed were "participants A."

Time for the laboratory to report the results
The period between the time that the HPV test was ordered to the laboratory and the results were reported by the laboratory was calculated. The participants to be analyzed were "participants A."

Time to send the results to the participants
The period between the time that the results were reported by the laboratory and the results were sent to the participants was calculated. The participants to be analyzed were "participants A."

Total time
The total period between the time that the second invitation letter was sent to the participants and the time that the HPV test results were sent to the participants was calculated. The participants to be analyzed were "participants A."

Incidence of adverse events
If adverse events were claimed by the participants, the percentage of those with adverse event(s) was calculated. The denominator is the number of participants who returned both a sample and a filled consent form. The numerator is the number of participants who reported each type of adverse event.